When it comes to optimal performance in Hyrox, understanding the physiological demands of the event is critical. Hyrox is unique—it’s not just about running a fast 10 km or excelling in strength-based workouts. The combination of running and functional fitness stations places a unique metabolic strain on the body, making the concept of the Maximum Metabolic Steady-State (MMSS) particularly relevant. Let’s dive into what MMSS is, why your 10 km race pace likely isn’t your MMSS, and how understanding MMSS can help you pace more effectively for Hyrox success.What is the Maximum Metabolic Steady-State?
The MMSS defines the boundary between exercise intensities where your body can maintain a steady physiological state and where it transitions into a non-steady-state. Below MMSS, markers like blood lactate, acid-base balance, and oxygen consumption stabilize at constant workloads. Above MMSS, these parameters progressively destabilize: lactate accumulates, acidity rises, and oxygen consumption increases until you hit your physiological ceiling.
This makes MMSS the cornerstone for determining sustainable pacing in Hyrox. Unlike threshold concepts derived from race times—such as 10 km or even half-marathon times—MMSS is a physiological marker, not just a performance metric. It accounts for what your body can handle metabolically rather than how fast you can run for a specific duration.
Why Your 10 km Time Isn’t MMSS
A common misconception among Hyrox athletes is equating their 10 km race pace with their MMSS. While a 10 km race tests your stamina, it typically involves running above your MMSS for significant portions. Hyrox, however, demands pacing closer to—or even slightly below—MMSS. This distinction is crucial:
- 10 km race pace: Likely exceeds MMSS, leading to a progressive build-up of lactate and fatigue.
- Hyrox pacing: Requires balancing metabolic demands to ensure efficient lactate clearance between running and functional fitness stations.
Relying on your 10 km time to determine Hyrox pacing can result in overestimating your MMSS, causing early fatigue and poor performance during later stations. This is why establishing MMSS through physiological testing, rather than race times, is essential.
Why Optimal Pacing is Slightly Sub-MMSS
The optimal pacing strategy for Hyrox aligns closer to half-marathon intensity than a 10 km effort. Running slightly below MMSS allows your body to:
- Maintain metabolic balance: Staying sub-MMSS ensures lactate levels remain manageable, reducing the risk of premature fatigue.
- Facilitate recovery: Lower intensities support more efficient lactate clearance between stations, enabling better performance in functional exercises.
- Enhance durability: Hyrox demands resilience over time, and a slightly sub-MMSS pace more likely allows you to sustain effort across the entire race duration.
This pacing strategy acknowledges that Hyrox is a hybrid endurance-strength event, requiring both aerobic efficiency and metabolic stability. Training and racing at a slightly sub-MMSS intensity strikes the perfect balance for maximizing performance.
How to Determine Your MMSS
There are several methods for identifying your MMSS. Here are the most relevant ones for Hyrox athletes:
- Incremental Step Test: This lab-based test involves measuring blood lactate levels at various intensities during exercise. MMSS is identified as the point where lactate begins to rise exponentially, signaling the transition to non-steady-state metabolism. While this test requires access to a lab, it provides one of the most accurate estimates of MMSS.
- Maximal Lactate Steady-State (MLSS): This method involves exercising at constant intensities for 30 minutes on multiple days. Blood lactate levels are measured throughout, and the highest intensity where lactate remains stable identifies your MMSS. Though time-intensive, MLSS is considered a gold standard for determining MMSS.
- Using Calculators: For athletes without access to lab testing, calculators can provide a more accurate estimate of threshold paces than simply relying on race times. Tools like the one from Endurox (available at Endurox Calculators) can help you approximate your MMSS based on training data, offering a practical and accessible alternative. These calculators consider various physiological inputs to refine your pacing strategy, making them more reliable than broad estimates from race times.
- Field-Based Estimates: While tests like Functional Threshold Power (FTP) and ramp tests are accessible, they often overestimate MMSS. For example, FTP is typically derived from a 20-minute effort, but the correction factor applied (e.g., 95%) may not align with individual physiology. Similarly, ramp tests rely on a fixed percentage of the final power output, which varies significantly among athletes. Care should be taken to interpret these results conservatively, particularly for hybrid events like Hyrox.
Practical Application in Hyrox Training and Racing
Understanding your MMSS has practical implications for pacing, recovery, and training:
- Pacing: Set your running effort during Hyrox slightly below MMSS. This ensures metabolic stability and optimizes performance across all stations.
- Training: Design sessions that target MMSS intensity to build metabolic resilience. Include intervals at or slightly below and above MMSS to simulate race demands.
- Recovery: Use MMSS heart rate zones to manage recovery between sessions, ensuring you’re not overtraining.
Conclusion
Hyrox is a challenging event that requires careful pacing to excel. By understanding and utilizing your MMSS, you can avoid the pitfalls of basing your strategy on race times like a 10 km effort. Instead, aim for slightly sub-MMSS pacing, which aligns closer to half-marathon intensity, to optimize lactate clearance and maintain performance across the entire race. MMSS isn’t just a concept—it’s a key to unlocking your potential in Hyrox.
Train smart, race smart, and embrace the science behind your success!
